i'm carol costello, on the same day a senate committee looks at the problem of gun violence in the united states, police work around the clock to save a 6-year-old boy held hostage by a man with a gun. for the past 17 hours that little boy has been held in an underground bunker in midland city, alabama, not far from the georgia border. police say the boy was taken after an armed man got aboard a school bus, demanded children, shot and killed the bus driver, and then fled to that underground bunker with the boy. neighbors describes what they've been told. >> i talked to the girl that was on the school bus and she told me he came on the bus with a gun, shot into the ceiling or the floor board once and shot the bus driver three times after asking for a child, two children between 6 and 8. the school bus driver apparently he did everything he could, he said you can't do that, threw the bus into reverse, floored the gas and that's when the bus alarm came on and tried to get out of the way but it was too late, he already shot the bus driver three times. >> our affiliate wdhn says the gunman is